Magnetite

Spectrum Details

Modality

NIR

Category

mineral

Material Type

Oxide

Sample ID

HS195.1B, HS195.2B, HS195.3B, HS195.4B

Collection Locality

Ishpeming, Michigan

Spectral Purity

1b2_3_4_ # HS195.1B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2_3_4_ # HS195.2B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2b3b4u # HS195.3B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns SPECTRAL_PURITY: 1b2_3_4_ # HS195.4B # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

Composition / XRD

None # XRF, EPMA, ICP(Trace), WChem COMPOSITION_TRACE:

Sample Description

Forms a series with Magnesioferrite and with Jacobsite. The spectrum of this sample was originally published in: Hunt, G.R., J.W. Salisbury, and C.J. Lenhoff, 1971, Visible and near-infrared spectra of minerals and rocks: III. Oxides and hydroxides. Modern Geology, v. 2, p. 195-205. With the note: "This sample is slightly contaminated with (spectrally neutral) quartz. Like the previous sample [HS78], it displays typically opaque behavior, decreasing in reflectivity with decreasing particle size. It is unusual in that it also exhibits a very weak band near 1.0µm due to the ferrous ion. The explanation for its opacity is as given above for [Magnetite HS78]." Grain size fractions are indicated by the extension after the sample number: .1B = IMAGE_OF_SAMPLE:

XRD Analysis

40 kV - 30 mA, 7.3-9.5 keV File: magnti195.out, -.mdi, ground once; mgt195-2.*, ground twice References: JCPDS 19-629; Huebner's reference patterns; SEM X-ray spectroscopy. Found: Magnetite, traces of an alkali feldspar (albite?), chlorite, and an unidentified phase with reflections at 3.31, 3.13, and 3.05 Angstroms. Comments: Magnetite is well crystallized and peak positions are consistent with Fe3O4 composition. SEM suggests grains containing Ca-Mn-Mg-Fe (carbonate?).

X Units

cm⁻¹

Y Units

Absorbance

Data Points

2,126